81549098525 has 12 divisors (see below), whose sum is σ = 101259998112. Its totient is φ = 65149526640.

The previous prime is 81549098513. The next prime is 81549098537. The reversal of 81549098525 is 52589094518.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81549098513) and next prime (81549098537).

It is not a de Polignac number, because 81549098525 - 2⁸ = 81549098269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2225267 + ... + 2261616.

It is an arithmetic number, because the mean of its divisors is an integer number (8438333176).

Almost surely, 2^81549098525 is an apocalyptic number.

It is an amenable number.

81549098525 is a deficient number, since it is larger than the sum of its proper divisors (19710899587).

81549098525 is a wasteful number, since it uses less digits than its factorization.

81549098525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4487620 (or 4487615 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 56.

The spelling of 81549098525 in words is "eighty-one billion, five hundred forty-nine million, ninety-eight thousand, five hundred twenty-five".